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authorThomas Gleixner <tglx@linutronix.de>2009-03-23 18:28:15 +0100
committerThomas Gleixner <tglx@linutronix.de>2009-03-24 12:15:23 +0100
commit3aa551c9b4c40018f0e261a178e3d25478dc04a9 (patch)
tree2a696109273fcc421d774cc8fefa4180331a85ad /include/linux/irqreturn.h
parent80c5520811d3805adcb15c570ea5e2d489fa5d0b (diff)
downloadlinux-linaro-stable-3aa551c9b4c40018f0e261a178e3d25478dc04a9.tar.gz
genirq: add threaded interrupt handler support
Add support for threaded interrupt handlers: A device driver can request that its main interrupt handler runs in a thread. To achive this the device driver requests the interrupt with request_threaded_irq() and provides additionally to the handler a thread function. The handler function is called in hard interrupt context and needs to check whether the interrupt originated from the device. If the interrupt originated from the device then the handler can either return IRQ_HANDLED or IRQ_WAKE_THREAD. IRQ_HANDLED is returned when no further action is required. IRQ_WAKE_THREAD causes the genirq code to invoke the threaded (main) handler. When IRQ_WAKE_THREAD is returned handler must have disabled the interrupt on the device level. This is mandatory for shared interrupt handlers, but we need to do it as well for obscure x86 hardware where disabling an interrupt on the IO_APIC level redirects the interrupt to the legacy PIC interrupt lines. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/irqreturn.h')
-rw-r--r--include/linux/irqreturn.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/irqreturn.h b/include/linux/irqreturn.h
index c5584ca5b8c9..819acaaac3f5 100644
--- a/include/linux/irqreturn.h
+++ b/include/linux/irqreturn.h
@@ -5,10 +5,12 @@
* enum irqreturn
* @IRQ_NONE interrupt was not from this device
* @IRQ_HANDLED interrupt was handled by this device
+ * @IRQ_WAKE_THREAD handler requests to wake the handler thread
*/
enum irqreturn {
IRQ_NONE,
IRQ_HANDLED,
+ IRQ_WAKE_THREAD,
};
typedef enum irqreturn irqreturn_t;